THE QUESTION NOT ASKED - THE CHALLENGE OF PLEIOTROPIC GENETIC TESTS

Nearly all of the literature on the ethical, legal, or social issues s urrounding genetic tests has proceeded on the assumption that any part icular test for a gene mutation yields information about only one dise ase condition. Even though the phenomenon of pleiotropy, where a singl e gene has multiple, apparently unrelated phenotypic effects, is widel y recognized in genetics, it has not had much significance for genetic testing until recently. In this article, I examine a moral dilemma cr eated by one sort of pleiotropic testing, APOE genotyping, which can y ield information about the risk of two different conditions-coronary h eart disease and Alzheimer's disease. A physician administering APOE t esting for the beneficial purpose of assessing the risk of heart disea se may discover medically useless and socially harmful information abo ut the patient's risk of Alzheimer's disease. I explore how much provi ders should disclose to patients about pleiotropic test results and wh ether patients are obligated to know as much about their genetic condi tion as possible.